| 摘要 |
PURPOSE:To enable smooth normal and reverse operations without using any extra component parts, by providing two holes having escaping slopes to an unlocking wheel at different radius positions and deforming the elastic projection of a rotary wheel in a transfer mode to make the projection escape through a reversing slope. CONSTITUTION:A rotary wheel 3 has elastic projections 6 and 7 which can be displaced toward the center of the wheel 3, and a unlocking wheel 2 contains holes 8 and 9 into which the projections 6 and 7 fall. Furthermore escaping slopes 8b, 8c, 9b and 9c are formed to the wheel 2. The projections 6 and 7 turn toward an arrow mark of a solid line from the position shown by a chain line in the figure and then fall into the holes 8 and 9 to escape through the slopes 8b and 9b respectively. When the projections 6 and 7 are turned reversely, they abut edge surface parts 8a and 9a of the parts 8 and 9 and then displaced toward the inner side to escape through the slopes 8c and 9c. A prescribed alarm switch is opened and closed by making use of a fall of the wheel 3. Thus smooth normal and reverse operations are ensured without using any extra component parts. |
